Ductile Design of Glued-Laminated Timber Beams
Publication: Practice Periodical on Structural Design and Construction
Volume 14, Issue 3
Abstract
Ductility is a fundamental component in the design of robust structures. For timber structures, the unfavorable material characteristics pose particular problems to its realization. Two approaches for improving the post-elastic behavior of glued-laminated timber beams have been investigated by testing and numerical analysis. The first is based on forming mixed beams with suitably assembled lamellae of different strength class; in the second, steel reinforcement is used. Satisfactory results have been obtained mixing laminations of different grade, whether from a single species or from different species, as long as the strengths of the lamellae are well differentiated. Steel-reinforced timber beams require taking special provisions in order to develop a ductile bending behavior, because material irregularities induce brittle failure of wood in tension before the steel bars may yield. Positive results were obtained, specifically preventing local failure modes, by releasing tension stresses in wood, by inserting small-diameter steel screws, or with a suitably balanced distribution of steel area. Steel reinforcement seemed once more capable of providing a simple and reliable solution.
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Acknowledgments
The writers thank Dr. Gaetano Castro of “Istituto di Sperimentazione per la Pioppicoltura,” Casale Monferrato, Italy, Mr. Franco Paganini, IVALSA, and Ing. Alessandro Fontanari for their important contribution to the realization of this research. The partial financial support of the Provincia Autonoma di Trento, Project CoDuLe (Ductile Behavior of Timber) and of the ReLUIS-DPA (Italian Emergency Management Agency) 2005–2008 Project is gratefully acknowledged.
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Information & Authors
Information
Published In
Practice Periodical on Structural Design and Construction
Volume 14 • Issue 3 • August 2009
Pages: 113 - 122
Copyright
© 2009 ASCE.
History
Received: Apr 21, 2008
Accepted: Jan 15, 2009
Published online: Jul 15, 2009
Published in print: Aug 2009
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